Vagotomy test apparatus



April 14, 1964 D, K. BAKER vmawom msw APPARATUS 4 Sheets-She et 1 Filed Aug. 21, 1961 April 14, 1964 D. K. BAKER 3,128,760

VAGOTOMY TEST APPARATUS Filed Aug. 21 1961 4 Sheets-Sheet 2 AIR SUPPLY RESERVOIR April 14, 1964 D. K. BAKER 3,128,760

VAGOTOMY TEST APPARATUS April 14, 1964 Filed Aug. 21, 1961 D. K. BAKER VAGOTOMY TEST APPARATUS 4 Sheets-Sheet 4 3,128,760 Patented Apr. 14, 1964 3,128,760 VAGOTOMY TEST APPARATUS David K. Baker, Heston, Middlesex, England, assignor to Winston Electronics Limited, Shepperton, England, a British company Filed Aug. 21, 1961, Ser. No. 132,748 9 Claims. (Cl. 128-2.1)

This invention pertains to an electromedical device in general and more specifically to an electrical device for testing the completeness of a nerve section during the operation of vagotomy.

In modern practice, the severance of the vagus or pneumogastric nerve is becoming one of the more important means for treatment of ulcers in the human patient.

There are three primary means of treating stomach ulcers. One is through a very stringent diet procedure, a second is surgically removing a section of the stomach itself and the third method is a nerve section of the vagus or pneumogastric nerve. It is the operation of vagotomy with which this invention is concerned.

The vagus nerve extends from the brain downwardly and has primary arterial trunks which follow and are associated with the esophagus. The vagus nerve trunks vary within individuals, some lying adjacent the outer wall of the esophagus, others passing within or through the esophagus wall with numerous branches extending therefrom. In all cases, however, the vagus nerves emerge from the esophagus approximately at the midpoint thereof. When the vagus nerve is stimulated by any means such as the swallowing of food, it causes gastric juices to be emitted into the stomach. When the food reaches the stomach, the gastric nerves are stimulated to provide an additional amount of these gastric juices. It has been determined that, due to the type of food now consumed in our civilization as opposed to the type of food that man ate in the early ages, this total amount of gastric juice emitted as a result of the stimulation of the vagus and gastric nerves is far in excess of that needed to digest the foods which we are eating today. Accordingly, stimulation of the vagus nerve in a patient suffering with ulcers, aggravates these ulcers an unnecessary amount by producing gastric juices which are not needed for digestive purposes. Therefore, a sevarance of the vagus nerve system would prevent the flow of gastric juices caused by the initial swallowing of food and therefore reduce the amount of gastric juices present in the stomach. This nerve section is normally performed at or near the area of the esophagus from which the vagus nerve emerges.

The major problem which has arisen concerning the operation of vagotomy is the lack of any method of determining if the nerve section has been complete during the operating period. As mentioned above, the vagus nerve trunks have numerous branches extending therefrom and these trunks and branches surround nearly the entire esophagus wall. If any one of the branches has not been severed, the stimulating of that single branch produces the same result as if the entire vagus nerve were intact.

Prior to this invention, the only method of determining or proving the complete nerve section in the operation of vagotomy was to complete the operation as could best be determined by the surgeon, and wait until the patient was able to swallow some food, thus determining if the swallowing of such food caused a reaction in the stomach at the time the food was passing down the esophagus. If such a reaction occurred, then the nerve section was incomplete and the operation would have to be performed again. The disadvantages of this procedure are obvious.

Accordingly, it is an object of this invention to provide a device for determining the completeness of the nerve section during the operation of vagotomy.

It is a further object of this invention to provide a device for locating the area in which the nerve section has not been completed.

A still further object of this invention is to provide a device for artifically stimulating the esophagus wall including the vagus nerve in order to determine if the operation of the vagotomy has been complete.

Another object of this invention is to provide a method of testing the completeness of the nerve section in the operation of vagotomy.

Yet another object of the invention is to provide a method of localizing the area in which a nerve section has not been completed in the operation of vagotomy.

Still another object of this invention is to provide apparatus for testing the completeness of the nerve section in the operation of vagotomy, which apparatus is of comparatively small size, adaptable for use during the operation and may be operated by portable apparatus.

Other objects become apparent from the description when taken in conjunction with the drawings wherein:

FIG. 1 is a plan view of the apparatus in use with a showing of a partial section of the esophagus and vagus nerve;

FIG. 2 is a partial showing of one tong of a forcep having the necessary electrodes mounted thereon;

FIG. 3 is a schematic diagram of the air supply system and measuring gauges;

FIG. 4 is a schematic diagram of the electrical system for supplying current to the electrodes during testing; and

FIG. 5 is a perspective View of the cabinet with the gauges, switches and air supply inlets to be used with the present invention.

Broadly speaking, the invention comprises an electrode means which is clamped about the esophagus after it appears that the nerve section has been completed. The electrode means are placed in contact with the outer esophagus wall by an inflatable device which is placed within the esophagus and inflated so as to block the esophagus and at the same time press the wall of the esophagus into contact with the spaced electrodes. The stomach is then inflated to a predetermined pressure and the electrodes are then connected to a voltage source. That portion of the esophagus between the two electrodes has an electric current passed therethrough, and, if the vagus nerve has not been completely sectionalized, the stimulation of the esophagus wall by the electrodes will in turn stimulate the vagus nerve and cause an injection of gastric juices into the stomach which will cause a stomach contraction and a change in the stomach gastric pressure. A measurement of this change of pressure is an indication that the vagotomy has not been completed.

Referring now to the drawings, FIG. 1 shows a section of the esophagus wall 10 and a portion of the vagus nerve 12 indicated therein. Inflating member 14 is shown within the esophagus and consists of a flexible outer sleeve member or cuif 16 which surrounds an air hose 24 passing therethrough with the ends 20 and 22 of the cult 16 being sealed to the airhose. The coil 16 may be made of any inflatable and flexible material such as rubber or a nylon reinforced rubber material. The cuff 16 has a mid-section 18 which is reduced in diameter for purposes which will become apparent as the description proceeds. The cuff 16 is inflated by means of a small air hose 30 which passes through the seal 20 and terminates within the cuff as indicated.

A large air hose 24 has openings 26 and 23 at one end thereof. A retaining ring 33 may be placed about the two hoses 24 and 30 and slidably mounted thereon in order to provide a means for preventing the patient from ingesting the cuff 16 beyond the esophagus and into the stomach.

A surgical forceps 34, 35 has secured at the outer ends thereof two semi-cylindrical units 42, 70 composed of a dielectric material. These dielectric units 42, FIG. 1 and 70, FIG. 3 are secured to each arm of the forceps in a manner such that they form a completed cylindrical surface when the forceps are in their clamped position. Accordingly, this cylinder composed of the elements 42 and 70 may be clamped about the esophagus wall as indicated in FIG. 1.

FIG. 2 shows one tong 35 of the forceps and the electrical connections and leads plus the electrodes associated with the forceps. In effect, the cylindrical dielectric attachments to the tongs contain, when in a clamped position, two cylindrical electrodes, each of these electrodes being split into four substantially identical overlapping sections, the sections shown in FIG. 2 being 74, 76, 78 and 80. The sections are preferably overlapped in order to eliminate the possibility of a small no sectioned nerve branch passing between the electrodes. It is to be understood that the other tong 34 carries an identical set of split electrodes and the electrical connections thereto are substantially the same as those to be described in connection with FIG. 2. As shown in FIG. 1 an insulated line 36 having an eight pin plug 37 at one end thereof and carrying therein eight separate electrical leads is strapped to the upper member of tong 35 and retained thereagainst by clamping means such as 38. The semi-cylindrical dielectric member 70 is secured to the end of tongs 35 by a securing means such as a screw 72. The electrical leads are split into two groups of four leads each at the upper end of the forceps with one four-wire group leading to the four electrical contacts 5, 6, 7 and 8 to the electrodes 74, 76, 73 and 80. These wires are held in place by a clamping means such as 48 and are embedded within the dielectric material so as to present a smooth outer surface about the cylindrical member 42, 70'. In a preferred method of designing the cylindrical dielectric, a channel may be formed in the outer portion of the cylinder so that the electrical leads may be contained therein to the point of attachment to the electrodes. A material, which is a dielectric such as a resin, may then be filled into the channel in order to cover the electrical leads and provide the desired smooth surface. It will now be evident the apparatus comprising the forceps and the electrical attachments thereto provides four separate but overlapping sets of electrodes. The method and means for energizing these electrodes will be described more in detail in connection with FIG. 4.

After the electrodes are in place and clamped thereon by the forceps 34 and 35, the inflatable cuff 16 and the stomach of the patient are inflated to a predetermined pressure. FIG. 3 is a diagrammatical illustration of the method of inflating and measuring the various pressure changes during the test used in the present invention. After the cuff 16 is inflated to a pressure wherein the esophagus is effectively blocked and the esophagus wall is pressed against the electrode members, the valve 54, which may be a two-way valve, is then turned so as to provide an air supply through conduit 52, conduit 24, the air hose passing through the cuff 16 and outwardly through the opening 28 which inflates the patients stomach. Associated with the conduit 24 by means of a separate conduit 56 is an air reservoir 58. Connected to and actuated by the pressure within the air reservoir are two pressure gauges 60 and 62. The gauge 62 is a direct conduit connection to the reservoir 60 and will indicate all of the fluctuations in the pressure within the stomach, even those due to the respiration of the patient. Primarily then, this gauge 60 is used to indicate that the system is operative and the stomach pressure variations are occurring. However, in order to properly read the gastric pressure and to inflate the stomach to a stabilized predetermined pressure, a conduit having a restriction 64 therein is connected to the gauge 62. This restriction 64 serves to dampen the smaller fluctuations of the very temporary type and thus gives a substantially stable reading on the gauge 62. The reading indicated on gauge 62 will hereafter be referred to as the gastric pressure reading. The separable connectors 66, 67, 68 are illustrated on the schematic in order to show that the equipment is adaptable to a portable device as will become apparent in the discussion of FIG. 5. The gauge 31 connected to conduit 30 by means of conduit 32 is provided in order to give an indication of the pressure to which the cuff has been inflated and to prevent an overinflation of this cuff.

In the preferred procedure, the cylindrical members 42 and 70 are placed about the esophagus at the location of the reduced mid-section of the cuff 16 which substantially coincides with the area wherein the nerve section was performed. The cuff is then inflated so as to block the stomach and at the same time force the outer esophagus wall against the electrodes in the dielectric cylinder. The stomach is then inflated to a predetermined pressure and the test for the completeness of the vagotomy may then proceed.

FIG. 4 is a diagrammatic illustration of the circuits and connections used in conjunction with the electrodes in performing this test. A manually operable indicating switch 112 is ganged for operation with switches 104, 106 and 108. If it were only desirable to determine the completeness of the vagotomy section without attempting to localize the area about the esophagus wherein the nerve section has not been completed, the two circular electrodes would not need to be split into the four sections as indicated and the position of the switches as shown in FIG. 4 would not be necessary. However, it is a great aid to the surgeon to be able to locate, at least within a quarter sectional area of the esophagus, that portion wherein the nerve section has not been completed. Accordingly, the use of the split cylindrical electrodes, when energized with the forceps placed in the same basic position as that shown in FIG. 1, will allow a stimulation of four separate sections of the esophagus wall. With this view of FIG. 1 being a plan view looking down upon the patient as he is lying on the operating table, the positions indicated are LA or left anterior, RA or right anterior, RP or right posterior and LP or left posterior and indicate the four quadrants about the esophagus wall.

In FIG. 4 a power supply is connected through a switch 92 which is biased to its open position and may be manually depressed to connect blocking oscillator 94 to power supply 90 with the output of the blocking oscillator being fed to an amplifier 96. This arrangement supplies a pulse output which is delivered to switch 104 through lead 98. With the manual switch 112 in the position shown at LA the switches 104, 106 and 108 also are in their positions as shown on the drawing. When the manual button 92 is depressed for a short period of time, the output of the amplifier is delivered to the electrode contact 1 of the cylindrical dielectric 42 through contact 1 of switch 104 and lead 116. The current then passes through that portion of the esophagus which is located between electrodes 1 and 2 which presents a resistance of approximately 1 kilohm between these two electrodes. Current passes from the contact 2 of the electrode, through lead 117 to a contact 2 of switch 106, through lead 118, through the switch arm of switch 108, through the milliammeter 110 and back to the negative side of the power source 90. The milliammeter 110 gives an indication that the circuit has been completed and also gives an indication of the approximate amount of current which passes through the esophagus wall. As the switch 112 is moved to its four different positions representing the four input electrodes 1, 3, 5 and 7, the same basic stimulation occurs as described above with the exception that each position switch stimulates a different quadrant of the esophagus wall. The battery position or BATT of the manual switch 112 opens switches 104 and 106 and connects the switch arm of the switch 108 to the contact 114. This position is designed to test the battery to make certain that it is sufficiently charged to operate the system. The output of the battery with the switch 92 depressed passes through lead 162 and through resistor 101 which is designed to match the approximate body resistance of 1 kilohm, through lead 100, contact 114 and thence through the milliammeter 110 and returns to the negative side of the battery.

As each quadrant of the esophagus is stimulated by positioning switch 112 and depressing switch 92, stimulation of each of the quadrants of the esophagus also stimulates the nerve systems therein including the vagus nerve. If the vagus nerve has not been completely severed in the particular quadrant being tested, this artificial stimulation of the vagus nerve will cause gastric juices to be ejected into the stomach and the stomach will contract, thus producing a noticeable rise in the gastric pressure. This rise can be detected and measured by gauge 62 which is connected to the reservoir 58 as explained above in connection with FIG. 3. If, after all four quadrants have been separately stimulated for the required amount of time, there has been no reaction which produces an increase in gastric pressure, the nerve section in the operation of vagotomy has been completed and the operation is finished. However, if any one quadrant when stimulated produces a noticeable rise in gastric pressure, then the surgeon will explore that quadrant further and complete the nerve section in that quadrant.

FIG. 5 illustrates a cabinet which may be used to provide a compact and easily read control and indicating console. The air hoses 24 and 30 are attached to the air input nipples 66 and 67 respectively. The main air supply may be provided by any of the well-known means such as compressors, compressed air supplies or even hand bellows through a flexible tubing to the nipple 68. The air pressure control switch 128 is connected to the twoway valve 54 and is turned in the counter-clockwise p0- sition to provide the necessary inflation of the cuff pressure, CP and in the clockwise direction to provide the gastric pressure to the stomach, GP. The dials 31, 60 and 62 are associated with the gauges represented schematically in FIG. 3. The eight pin socket 124 is provided for receiving the eight pin plug 37 which supplies the leads to the necessary electrodes attached to the forceps. Milliammeter 110 is read in association with the position of the switch 112 with the circuitry, including a blocking oscillator and amplifier, being enclosed within the cabinet. Switch 92 is the spring biased switch which is biased in the normally open position and is manually depressed by the person conducting the test.

The normal procedure used in conducting the test is to insert the cuff 16 into the esophagus until it is located in the lower esophagus passage with the stomach inflating tube 28 extending therethrough. The electrodes are clamped about the reduced center portion of the cufl 16 and the cuff is then inflated. As pointed out above, inflation of the cuff blocks off the esophagus and at the time assures that the esophagus wall will be pressed firmly against the split electrodes. The stomach is then inflated to a predetermined gastric pressure as read on the gauge 62. Each quadrant of the esophagus is then artificially stimulated by an electrical charge for approximately one minute by depressing the manual switch 92, and the pressure gauges are observed to determine any reaction which causes an increase in the gastric pressure. Thus, it can be seen that a very accurate method of determining the completeness of the nerve section during the operation of vagotomy is provided by this invention.

Modifications in the construction and arrangement of the parts and the circuits shown may be made Within the spirit and scope of the invention and such modifications are intended to be covered by the appended claims.

I claim:

1. A device for testing the completeness of the severance of the vagus nerve comprising means for blocking the passage between the esophagus and the stomach, means for creating a predetermined pressure within the stomach, a pair of arcuate electrodes adapted to substantially surround the esophagus, means for pressing the outer wall of the esophagus against said electrodes, means for energizing said electrodes whereby that portion of the esophagus including the vagus nerve between said electrodes is electrically stimulated, and means for measuring the change in said predetermined pressure.

2. Apparatus for testing the completeness of the nerve section in the operation of vagotomy comprising means for blocking the esophagus passage, means for inflating the stomach to a predetermined pressure, electrical means for artificially stimulating the esophagus wall, and means for measuring the change in said predetermined pressure during said stimulation.

3. The apparatus of claim 2 wherein said means for blocking the esophagus comprises an inflatable cult within the esophagus.

4. The apparatus of claim 2 wherein said means for artificially stimulating the esophagus Wall comprises at least one set of arcuate electrodes for substantially surrounding and passing an electrical current through said esophagus wall.

5. Apparatus for testing the completeness of the nerve section in the operation of vagotomy comprising a flexible hose adapted to pass through the esophagus and into the stomach, an inflatable cuff surrounding said hose within the esophagus, means for inflating said cutf so as to block the esophagus passage, means for inflating the stomach to a predetermined pressure through said hose, a pair of spaced circular electrodes adapted to surround the outer esophagus wall and said cuff, said esophagus wall being forced into contact with said electrodes when said cuff is inflated, means for energizing said electrodes and the esophagus wall therebetween including the vagus nerve associated therewith, and means associated with said hose for measuring the change in said predetermined pressure during the time that said electrodes are energized.

6. The apparatus of claim 5 wherein each of said circular electrodes are split into four overlapping quadrants and said energizing means includes means for energizing each of said quadrants separately.

7. The apparatus of claim 6 wherein said electrodes are mounted within a dielectric split cylinder, said cylinder surrounding said esophagus.

8. The apparatus of claim 7 wherein said split cylinder is associated with a surgical forceps for clamping said cylinder about said esophagus Wall.

9. A device for testing the completeness of the severance of the vagus nerve comprising a hose open at one end thereof, means for supplying air under pressure to the other end of said hose, a flexible cuff sealed to an intermediate portion of said hose, means for inflating said cuff, at least two arcuate electrodes substantially surrounding said cutf, means for energizing said electrodes, and means for measuring the pressure within said hose.

Quigley et al.: Digestive Tract, pages 280-292 of Medical Physics, vol. 11, published 1950 by Year Book Publishers, Chicago. 

1. A DEVICE FOR TESTING THE COMPLETENESS OF THE SEVERANCE OF THE VAGUS NERVE COMPRISING MEANS FOR BLOCKING THE PASSAGE BETWEEN THE ESOPHAGUS AND THE STOMACH, MEANS FOR CREATING A PREDETERMINED PRESSURE WITHIN THE STOMACH, A PAIR OF ARCUATE ELECTRODES ADAPTED TO SUBSTANTIALLY SURROUND THE ESOPHAGUS, MEANS FOR PRESSING THE OUTER WALL OF THE ESOPHAGUS AGAINST SAID ELECTRODES, MEANS FOR ENERGIZING SAID ELECTRODES WHEREBY THAT PORTION OF THE ESOPHAGUS INCLUDING THE VAGUS NERVE BETWEEN SAID ELECTRODES IS ELECTRICALLY SIMULATED, AND MEANS FOR MEASURING THE CHANGE IN SAID PREDETERMINED PRESSURE. 